Frontier Airlines saw a 3.8 percent increase in passengers in August from a year earlier, the Denver-hubbed carrier reported Tuesday.

Frontier counted 1,458,249 passengers last month, up from 1,405,050 in August 2010.

That follows a year-over-year increase of 2.2 percent in July, a 1 percent decline in June, a 4.1 percent increase in May and a 0.9 percent decline in April, following year-over-year increases over the previous several months.

Frontier is the No. 3 carrier at Denver International Airport, behind United Airlines and Southwest Airlines.

The airline’s revenue passenger miles — the number of paying passengers times miles flown — rose 1.7 percent in August from a year earlier, to 1.234 billion, the airline reported.

Frontier’s capacity — a measure of the seats available to carry passengers, expressed as available seat miles — was down 0.9 percent in August from a year earlier, to 1.371 billion.

Its load factor — the percentage of its capacity actually used by passengers — rose by 2 percentage points from a year earlier, to 90 percent.

Indianapolis-based Republic Airways Holdings Inc. (Nasdaq: RJET) acquired Frontier in October 2009. The totals include both Frontier and Midwest Airlines, which are now being consolidated.

Separately, Republic said that all its planes — including those it flies as a contract carrier for other airlines — flew 2,936,352 passengers last month, down 1.8 percent from August 2010.